A typical CMOS image sensor includes a photodiode area for receiving an optical signal to convert the optical signal into an electrical signal, and a transistor area for processing the electrical signal.
According to the related art, the photodiodes and transistors are horizontally disposed in the CMOS image sensor.
In other words, in the CMOS image sensor according to the related art, the photodiodes and the transistors are positioned on a substrate such that they are horizontally adjacent to each other. Accordingly, additional areas are required for the photodiodes. For this reason, a fill factor area may be reduced, and resolution may be restricted.
Furthers the CMOS image sensor according to the related art has difficulties in optimizing the manufacturing process when the photodiodes and the transistors are simultaneously manufactured.
In addition, in the CMOS image sensor according to the related art, if the size of a pixel increases, the resolution of the CMOS image sensor may decrease. Likewise, if the area for the photodiode decreases, the sensitivity of the image sensor may decrease.